Night-flying hawkmoths face a problem. They feed on the nectar in flowers, and, although their vision is sufficient to find the flowers, it is not accurate enough to locate the tube leading to the nectar. So once a moth finds a flower, how does it locate the nectar?

Joaquin Goyret, a graduate student in Robert Raguso's laboratory, noticed that the grooves in the petals of flowers always pointed to the nectar. By making artificial flowers, some with grooves that led to the nectar and some with grooves that did not, he was able to demonstrate that these moths use their tongues as probes, following the grooves to the sweet reward.